Modern computing and communication devices incorporate electronic systems such as chips, hybrids, microprocessors, connectors, and miniature circuit boards, to mention a few representative examples. The circuitry of these electronic systems typically utilizes many different materials, structures, and components that have substantially different thermal expansion properties. Manufacture often involves a reflow process in which the circuitry is heated to a sufficient temperature to produce solder flow.
In the heating process, the circuitry's different materials expand differently, resulting in strains and stresses that can negatively impact reliability if not properly taken into account during circuit design. For example, polymers, composites, metals, glasses, films, and ceramics in the circuitry can expand at different rates when heated during reflow and can contract differently during subsequent cooling.
Engineers may model and attempt to account for the different thermal expansion characteristics of the circuitry elements during design. However, there is typically deviation between conventional models and the actual performance during mass production reflow. Some of this deviation may be due to a conventional model's inability to account fully for the way the circuitry is heated during mass production. When the deviation between modeled and actual performance is sufficiently large to cause a reliability issue, the circuit design typically needs to be modified. However, redesigning a circuit after the circuit is in mass production can cause product release delays and substantial expense. Accordingly, circuit designers need information early in the design process about how their designs will behave in the thermal environment and operating conditions of a mass production reflow process.
For example, technology is needed for emulating parameters or conditions of a circuitry heating process of a mass production reflow process. Need exists for simulating heating and mechanical results associated with a reflow process. Need exists for a system that can heat a sample, such as an electronic system or circuitry or some other device, precisely. Need exists for a system that can heat a sample uniformly. Need exists for a system that can heat a sample using convection. Need exists for a system that can provide or facilitate dimensional measurements of a sample while the sample is being precisely heated, for example under conditions emulating a reflow process.
There is further need in the art for an improved approach to heating samples while measuring them optically, such as with high-resolution shadow moiré technology, to better simulate what happens in a production reflow oven. There is further need in the art for a means to heat a sample in a confined space, such as when a physical glass grating of a shadow moiré instrument is located adjacent a measured surface. A capability addressing one or more such needs, or some other related deficiency in the art, would support better heating, modeling, and metrology.